1. Field of the Invention
The present invention relates to a roaming service providing method and system, and more particularly, to an inter-network roaming service providing method and a system thereof.
2. Description of the Related Art
Roaming is a service that also allows a user to perform communication in service zones of different communication enterprisers. For example, there are two PCS portable phone enterprisers in Korea. The two PCS portable phone enterprisers construct respective separate service networks. Accordingly, the respective enterprisers may have excellent service zones and bad service zones. In this case, it would be convenient for different enterprisers to contract such that users may have a service of excellent quality by connecting service networks to each other although users join in any enterprisers as members. A roaming service is a service that extends quality and areas of a service by contracting communication enterprisers.
An existing roaming service in a communication network provides a voice service through roaming between enterprisers (e.g., Korean-Japanese 3G network enterprisers) using the same access technology or CS network enterprisers (e.g., GSM-WCDMA enterprisers or CDMA-WCDMA enterprisers) using different access technologies.
The existing roaming service has provided only roaming between enterprisers providing the foregoing technology and CS network enterprisers. However, as a network is gradually expanded to an IP and an IP based voice service has been extended, there is a need for a method that allows a subscriber receiving a voice service with the same terminal to roam to a CS network of another enterpriser in another zone for receiving the voice service.